Cycletron 0.1.0-alpha.27

Dialect

Patterns in Cycletron run on strudel-rs, not the browser Strudel (strudel.cc) runtime. Most mini-notation is compatible; these differences cause the most silent or broken output.

For the full supported surface see STRUDEL_RS_SUPPORTED.md.

Critical rules

1. Pan is 0…1 (not −1…1)

0 = full left, 0.5 = center, 1 = full right.
Negative pan → NaN in the panner → complete silence.

// good
.pan(0.3)
.pan(sine.range(0.2, 0.8))

// bad — silent
.pan(-0.3)
.pan(sine.range(-0.3, 0.3))

2. chord() needs .voicing()

Without .voicing(), the chord symbol is treated like a sample name → silence.

// good
chord("<Cm7 FM7>").voicing().s("supersaw")

// bad — often silent
chord("<Cm7 FM7>").s("supersaw")

3. .scale() needs "root:mode"

// good
note("0 2 4 5 7").scale("C4:minor")

// bad — no-op
note("0 2 4 5 7").scale("minor")

Scale only quantizes numeric degrees, not absolute names like c4.

4. pickRestart needs .slow(n) on the selector

Without .slow(), each section lasts one cycle (~1–2s at dance tempos).

// good — ~8 cycles per section
"<intro chorus drop>".slow(8).pickRestart({
  intro: s("bd*4"),
  chorus: s("bd*4, hh*8"),
  drop: s("bd*4, ~ cp ~ cp, hh*8"),
})

// bad — sections flash by
"<intro chorus drop>".pickRestart({ ... })

Rough guide at 140 BPM: .slow(4) ≈ 7s, .slow(8) ≈ 14s, .slow(16) ≈ 27s.

5. Commas inside < > don't stack — they split slots

Spaces separate items in slowcat. Commas stack only inside [ ] / { } or at the top level of a mini-notation string. Inside < > a comma still parses, but it means something else entirely: each comma-separated group becomes one alternating slot, so nothing plays together.

// good
note("<c2 g2 a2 f2>")
note("<[c3,e3,g3] [f3,a3,c4]>")
s("bd, sd")

// bad — parses, but each note becomes its own slot instead of stacking
note("<c2, g2, a2, f2>")
note("<[c3,e3,g3], [f3,a3,c4]>")

6. Random choice | only inside [ ] or { }

// good
s("[bd | sd]")

// bad
s("<bd | sd>")

7. Tempo and syntax hygiene

  • Prefer setbpm(120); with parentheses and a semicolon.
  • Prefer double quotes for mini-notation, though '…' and `…` also parse.
  • .bank("RolandTR808") works for the built-in machine kits (RolandTR808/909/707/606/727, LinnDrum, BossDR55); only arbitrary custom sample banks are unsupported.
  • Euclid rotation must be a literal number: bd(3,8,1) not a nested pattern.

Quick self-check

If something is silent or errors on eval:

  1. Check pan, voicing, and scale format first.
  2. Check commas inside < >.
  3. Ask the AI to run validate_pattern, or validate from the agent tools.
  4. Help → Show Logs for the exact parser message.

From docs/DIALECT.md at v0.1.0-alpha.27.